A blog documenting projects and ideas

Plastic trolley experiment results

This post will be periodically updated with any experiments I do involving the plastic trolley. Here is a picture of the new trolley:

It has two baskets in it. The bottom one contains the RFID reader, it will also hold a battery in the future. The top basket is used for holding products in. This set of experiments will be similer to the ones done with the metal trolley. It will be interesting to compare the results to see which type of trolley is more suitable to use for the application of a ‘smart trolley’. This time instead of making a separate post for each experiment, all results will be posted here for convenience.

Testing how easily tags are read outside of the trolley:

This was the experiment set up:

This experiment is important because we need to know if the trolley might read tags that are in other trolleys or maybe still on the shelves. Only tags that are placed inside the trolley should be read.

Success rate of reading tags put in the trolley:

Because this trolley is much smaller and is made of plastic, it does not suffer from the ‘blind spots’ that the metal trolley did. So I got started straight away with filling the trolley with products and trying to read them all at once:
The success rate was almost always 100% with the tags fixed to the products in a straight posision (not bent around corners) even at 15db (which is the lowest transmit power the reader will go down to). The reason why the success rate was not always 100% is because occasionally two products would be placed in the trolley and the tags would be touching. This causes both tags to be undreadable.
Here is an example of the tags touching that would cause problems:

Maybe if the tags are bent this will solve the problem:

Bending the tags makes a big difference. This way no matter what orientation, even if the tags are touching there is some of the tag sticking out.